Pinking device for sewing machines



y Z3, J. BRUSSELL' 2,049,351

PINKING DEVICE FOR SEWING MACHINES Filed June 22, 1935 INVENTOR JacobBrussell Patented July 28 1936 PATENT OFFICE PINKING DEVICE FOR SEWINGMACHINES Jacob Brussell, New York, N. Y., assignor to Isadore Friedman,Roselle, N. J.

Application June 22, 1935, Serial No. 27,910

15 Claims. 01. 112-422) My invention relates to pinking devices forsewing machines, and in more detail, to improvements and changes in thepinking device which is the subject of my Letters Patent Number2,010,216, granted August 6, 1935.

In the pinking devices now produced numer-r ous different spring meansare used to forcea close contact between the knife blade and theshearing plate but these spring means often cause excessive wear of theknife blade and shearing plate; They do not prevent the knife blade frombeing held stuck against the shearing plate and do not aid in liftingthe knife blade after the cutting action is finished anddo not give adesirable increasing pressure on the down stroke of the blade and adecreasing pressure on the up stroke. In addition, the present devicesare not easily or finely adjustable. The construction of the knifeblades and shearing plates is such that there is a tendency for theblade to dull quickly and for the blade to catch or be held in theshearing plate, the cloth wedging the two together.'

It is an object of my invention to produce a pinking device with aspring means which will force a close contact'between the, knife bladeand the shearing plate in such a manner that there is a minimum of wearof the shearing plate and knife blade cutting edges, give a proper and asufliciently directed force to prevent clogging of the moving parts, andproduce a spring action which causes an increasing pres-.

sure of the knife blade against the shear plate on the downward strokeof the knife blade' and a decreasing pressure of the knife blade againstthe shear plate on the upward stroke of the knife blade and in addition,to provide an upward pressure on the knife element aiding its upwardstroke.

Another object of my invention is to provide a simple strong pinkingdevice in which the spring means is easily removed and finelyadjustable.

A further object of my invention is to construct a pinking device inwhich there is a minimum of wear of the knife blade and shearing plateand in which the knife blade and shearing plate are so constructed thatthere will be no tendency for the cloth to become wedged between theknife blade and shearing plate and hold the two together.

I accomplish these objects by constructing a pinking device in whichthere is provided a coiled spring functioning against one arm of anangled pivoted bar, attaching to the knife of the pinker an extensionprovided witha roller co-acting with the other arm of the bar and byproviding a concave face on the under surface of the knife and 'byconstructing the side faces of the shearing plate past which the knife Vpasses with an angle of less than 90 degrees. 6

Further and more specific objects, features and advantages will moreclearly appear from the detailed description given below taken inconnection with the accompanying sheet of drawings which forms a part ofthis speciflcation.

Figure 1 of the drawing is a side view partly in section of my pinkingdevice attached to a sewing machine, Fig. 2 is a plan view of my pinkingdevice with the upper parts removed to show the base part and springmeans more clearly, Fig. 3 is a vertical section through the center ofthe knife blade showing a detail and Fig. 4 is a detail showing theshear plate. In the drawing, l represents the base and 2 the head 0 witha needle attached of an ordinary sewing machine. The base I of themachine is cut away at 3 to provide room for parts of the pinker 4 whichextend downward below the. base of the machine.

The pinker 4 is positioned on the base I of the sewing machine and isconstructed with the base plate 5, bearing and shaft 6 and arm I in themanner described in my above mentioned patent application. means 8,pivot arm 9 and pin ID are also constructed as described in the abovementioned application so that the reciprocation of the driving means 8causesthe arm 9 and pin III to reciprocate.

Attached to the pin I0 is the fork H which holds the knife element [2.This knife element, in general, is constructed similar to,the knifedescribed in the previous application, but difiers in the respect thatthe under face l3 of the knife is concave shaped, undercut or scoop dout so that the angle between a side face I and the under face I3 isless than degrees and so forms a, sharp cutting edge. As in the previousIn addition, the driving 30' material, and to prevent excess wear of theknife faces, the lower part of the side wall I6 of the shear plate I5 iscut away so that the angle between the face of the shear plate l5 andthe side wall I6 is less than degrees.

By constructing the side wall of the shear plate in this way, only theupper edge of the wall touches the knife blade and so, little'wear iscaused to the knife blade and as the lower part of the side wall of theshear plate slopes away from the knife blade, more room is provided sothat waste material cut off can fall away and eliminate the possibilityof clogging the knife against the shear plate.

In order to force a knife blade against the shearing plate, a springmeans is provided which is constructed partly on the arm I, the baseplate 5 and the knife fork H. V

The part of the spring means constructed on the arml extends through ahole H in the arm. A tube I8 is internally threaded at l9 on the outerend and externally threaded at 20 into' corresponding threads in theopening H. A rod 2| tipped at the lower end with the, shouldered contacthead 22 rests in the tube I8, and the head 22 projects through theopening IT. The upper end of the rod 2| is provided with a sleeve 23which is threadedinto the threaded part l9 of the tube. The outer end ofthis sleeve has an enlarged knurled head. A knurled threaded washer 23Ais provided on the threaded part of the sleeve-so that it can be screwedclose to the end of the tube. Extending around the rod 2| between theshouldered head 22 and the lower end of the sleeve 23 is a coiled spring24 for providing the compression for the spring means.

Extending from the rear of the knife fork II is an arm, contact piece orlink 25 which, after a bent part 26, terminates in a bearing 21 carryinga roller 28.

A bearing 29 is constructed on the base 5 and is provided with a pin orpivot 30 to carry the bent arm or lever 3|. The upper part of the arm 3|is bent slightly to form a suitable resting place against .which thehead 22 can rest. The other part of the arm 3| is straight and forms abearing for the roller 28.

The upper end of the spring 24 rests against the fixed sleeve part 23while the lower end pushes the head 22 outwardbeyond the arm 1 andagainst the upper part of the arm 3|, thus forcing the lower part of thearm 3| forward against the roller 28. This causes the knife to be pushedforward against the shear plate and gives the necessary compression forcutting. The fact that the lower part of the arm 3| extends forward atits lower part causes an increased pressure of the knife blade againstthe shear plate as the knife and roller descend. Because of the forwarddirection of the lower part of the arm 3|, there is produced in additionto the necessary cutting compression and upward component which tends toaid the driving means in raising the knife. The compression of thesystem is regulated by turning the knurled sleeve which causes acorresponding change of pressure in the spring 241 and throughout theentire spring parts.

While I have described my improvements in great detail and with respectto a preferred form thereof, I do not desire to be limited to suchdetails and forms since many changes and modifications may be made andthe invention embodied in widely different forms without departing fromthe spirit and scope thereof in its broader aspects. Hence I desire tocover all and a bearing means on said extension to bear modifications,forms and embodiments coming within the language or scope of any one ormore of the appended claims.

I claim:

1. A pinking device for a sewing machine hav- 5 ing a base plate, abearing on said plate, an arm pivotally held in the bearing, a knifeheld by the arm, a shear plate against which the knife cuts. and aspring means comprising a hollow-tube extending from the arm, a rod insaid tube extending through said tube and projecting beyond the arm, aspring in said tube about said rod and extending and providing springaction between the rod and tube, a bearing on said base plate, an angledbar pivoted in the bearing, an extension on said knife and a bearingmeans on said extension to bear against one part of the angled bar whilethe other part of the angled bar rests against the rod causingcompression in the spring.

2. A pinking device for a sewing machine having a base plate, a bearingon said plate, an arm pivotally held in the bearing, a knife held by thearm, a shear plate against which the knife cuts, and the spring meanscomprising a hollow tube extending from the arm, a rod in said tubeextending through said tube and projecting beyond the arm, a spring insaid tube about said rod and extending and providing spring actionbetween the rod and tube, a bearing on said base plate, 30 an angled barpivoted in the bearing, the bar so angled that one part extends from theangle downward toward thebase plate and forward toward the knife, anextension on said knife against the downward forward part of the angledbar while the other part of the angled bar rests against the rod causingcompression in the spring.

3. A pinking device for a sewing machine having a base plate, a bearingon said plate, an arm pivotally held in the bearing, a knife held by thearm, a shear plate against which the knife cuts, and a spring meanscomprising a hollow tube extending from the arm, a rod in said tubeextending through said tube and projecting beyond the arm, a spring insaid tube about said rod and extending and providing spring actionbetween the rod and tube, a bearing on said base plate, an angle barpivoted in the bearing, the bar so angled that, one part extends fromthe angle downward toward the base plate and forward toward the knifewhile the other part extends from the angle backwards toward the arm andcurves downward near its end to form a bearing place against which therod end rests, an angled extension on said knife and a roller means onsaid extension to bear against the downward forward extending part ofthe angled bar while the downward curving part of the bar through therod compresses the spring.

4. A pinking device for a sewing machine having a base plate, a bearingon said plate, an arm pivotally held in the bearing, a knife held by thearm, a shear plate against which the knife cuts, and a spring meanscomprising a hollow tube 35 threaded at its outer end extending from thearm,

a rod in said tube extending through said tube and arm, a sheath aboutsaid rod having a head at its upper end and threaded at its lower endinto the threaded end of the tube, a spring in 7 said tube about saidrod and extending and providing spring action between the rod and sheathpart threaded to the tube, said head part of the sheath being turned tovary the spring compression, a bearing on said base plate, an angled bar75 pivoted in the bearing, an extension on said knife and a bearingmeans on said extension to bear against one part of the angled bar whilethe other part of the angled bar rests against the rod causingcompression in the spring.

5. A pinking device for a sewing machine having a base plate, a bearingon said plate, an arm pivotally held in the bearing, a knife held by thearm, a shear plate against which the knife cuts; and a spring meanscomprising a spring, a carrier and holding means for the spring, and afunctioning means through which the spring acts comprising a bearing onsaid base plate, an angled bar pivoted in the bearing, an extension onsaid knife and a bearing means on said extension to bear against onepart of the angled bar while the other part of the angled bar restsagainst the spring holding means.

6. Apinking device for a sewing machine having a base plate, a bearingon said plate, an arm pivotally held in the bearing, a knife held by thearm, a shear plate against which the knife cuts, and a spring meanscomprising a hollow tube threaded at its outer end extending from thearm, a rod in said tube extending through said tube and arm, a sheathabout said rod having a head at its upper end and threaded at its lowerend into the threaded end of thetube, a spring in said tube about saidrod and extending and providing spring action between the rod and sheathpart threaded to the tube, said head part of the sheath being turned tovary the spring compression, a bearing on said base plate, an angled barpivoted in'the bearing, the bar so angled that one part extends from theangle downward toward the base plate and'forward toward the knife whilethe other part extends from the angle backwards toward the arm andcurves downward near its end to form a bearing place against which therod end rests, an angled extension on said knife and a roller means onsaid extension to bear against the downward forward extending part ofthe angled bar while the downward curving part of thelbar through therod compresses the spring.

'1. A pinkingdevice for a sewing machine having a base plate, a bearingon said plate, an arm pivotally held in the bearing, a knife held by thearm, a shear plate against which the knife cuts, and a spring meanscomprised of a spring attached to the arm, a bar, and a roller attachedto the knife, the spring operating through the bar and roller to causethe knife to press against and cut in conjunction with the shear plate.

8. A pinking device for a sewing machine having a base plate, a bearingon said plate, and arm pivotally held in the bearing, a knife held bythe arm, a shear plate against which the knife cuts, and a spring meanscomprised of a spring attached to said arm, a bearing on the base plate,an angled bar pivotally held in the bearing, and a roller attached tothe knife, the spring operating against one part of the angled bar tocause the other part to press against the roller to cause the knife tocontact with the shear plate. P 9. A .pinking device for a sewingmachine having a base plate, a bearing on said plate, an arm pivotallyheld in the bearing, a knife held by the arm, a shear plate againstwhich the knife cuts, and a spring means comprised of a spring attachedto said arm, a bearing on the base plate, an angled bar pivotally heldin the bearing, an arm attached to the knife and means on the arm, thespring operating against one part of the angled bar to cause the otherpart to press against the means on the arm of the knife to cause theknife to contact with the shear plate. 5

10. A trimming mechanism for sewing machines comprising a base, an armpivoted on said base, means attached to said arm for reciprocating thesame, a knife pivoted on the free end of said arm, a ledger bladecooperating with said 10 knife, a spring mounted on the rear of saidarm, a pivoted lever between said spring and knife, said spring actingupon said lever, and a contact piece secured to said knife andoperatively engaged with said lever.

11. A trimming mechanism for sewing machines comprising a base, an armpivoted on said base, means attached to said arm for reciprocating thesame, a knife pivoted on the free end of said arm, a ledger bladecooperating 20 with said knife, 9. spring mounted on the rear of saidarm, a pivoted lever mounted on said base between said spring and knife,said spring acting upon said lever, and a contact piece secured to saidknife and operatively engaged with said 25 lever.

12. A trimming mechanism for sewing machines comprising a base, an armpivoted on said base, means attached to said arm for reciprocating thesame, a knife pivoted on the free end of 30 said arm, aledger bladecooperating with said knife, a. coil spring mounted on the rear of saidarm, a pivoted lever between said spring and knife, said spring actingupon said lever, and a contact piece secured to said knife andoperatively engaged with said lever.

13. A trimming mechanism for sewing machines comprising a base, an armpivoted on said base, means attached to said arm for reciprocating thesame, a knife pivoted on the free end of said arm, a ledger bladecooperating with said knife, a. spring mounted on the rear of said arm,

a. screw threaded member contacting with the end of said spring andadapted to be manipulated to vary the tension of said spring, a pivotedlever between said spring and knife, said spring acting upon said lever,and a contact piece secured the tension thereof, a pivoted lever betweensaid spring and knife, said spring acting upon said lever, and a contactpiece secured to said knife and operatively engaged with said lever.

15. A trimming mechanism for sewing machines comprising a base, an armpivoted on said base; means attached to said arm for reciproeatingthe'same, a knife pivoted on the-free end of said arm, a ledger bladecooperating with said knife, a spring mounted on the rear of said arm, apivotedlever between said spring and knife, said spring acting upon saidlever, and a contact piece secured to said knife andloosely engaged withsaid lever.

I JACOB BRUSSELL.

